A dart is inserted into a spring- loaded dart gun by compressing the spring in b

Question

A dart is inserted into a spring- loaded dart gun by compressing the spring in by a distance x. For the next loading, the spring is compressed a distance 2x. How much work is required to load the second dart compared with the first? 3. (a) four times as much (b) twice (c) the same (d) one-half (e) one-quarter How much faster does the second dart leave the gun compared with the first? (a) four times as fast (b) two times (c) the same (d) one-half (e) one-quarter 4. Choose the correct answer. The gravitational potential energy of a system (a) is always positive (b) is always negative (c) can be negative or positive 5. If the net work done by external forces on a particle is zero, mark which of the following statements about the particle must be true (a) Its velocity is zero (b) Its velocity is decreased (c) Its velocity is unchanged (d) Its speed is unchanged (e) More information is needed 6. What does the slope of a graph of U(x) versus x represent? (a) the magnitude of the force on the object (b) the negative of the magnitude of the force on the object (c) the x component of the force on the object (d) the negative of the x component of the force on the object

Explanation / Answer

3. work done = 1/2 *k*x2

so if x is doubled then work is four times.

by conservation of energy

1/2*k*x2 = 1/2*m*v2

so if x doubled then speed is two times.

4.. gravitational potbtial energy can be negative or positive as it depends on reference level.

5. work = force* displacement = force*velocity*time

so if work zero then velocity is also zero.

6. slope represents the negative of the magnitude of force.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.